Furnace equipped with cleaning apparatus



Dec. 22, 1964 N. w. ROUDABUSH FURNACE EQUIPPED WITH CLEANING APPARATUS 5Sheets-Sheet 1 Filed June 13, 1962 INVENTOR. NED W. ROUDABUSH "FR-P1366- 1964 N. w. ROUDABUSH FURNACE EQUIPPED WITH CLEANING APPARATUS 5Sheets-Sheet 2 Filed June 15, 1962 mw mm m0 m@ R 90 mm, N m

W Ms Wm fnw w a ?w NE Dec. 22, 1964 N. w. ROUDABUSH 3,162,151

FURNACE EQUIPPED WITH CLEANING APPARATUS Filed June 13, 1962 5Sheets-Sheet 3 1 "luv l 55' RR I 12 5 IHHHl.

Inventor NED W.ROUDABUSH mum Dec. 22, 1964 N. w. ROUDABUSH 3,162,151

FURNACE EQUIPPED WITH CLEANING APPARATUS Filed June 13, 1962 5Sheets-Sheet 4 Inventor NED W.ROUDABU$H 1964 N. w. ROUDABUSH 3,162,151

FURNACE EQUIFPED WITH CLEANING APPARATUS Filed June 15, 1962 1 5Sheets-Sheet 5 Invent o r N ED ,W. RouoA BUSH walfm K121 4mmA'H-orltelis I United States Patent Gfitice 3,lfi2,l l Patented Dec.22., 1964 This invention relates to apparatus for maintaining clean thetops of furnace walls, such as metallurgical furnaces and the like,constructed from suspended refractory bricks. This invention alsorelates to a way of suspending bricks in the roof of an open hearth orlike metallurgical furnace.

This application is a continuation-in-part of application Serial No.816,143, filed May 27, 1959, and now abandoned. Furnaces such asopen-hearth furnaces and the like are usually constructed with a roof ortop wall comprising suspended refractory bricks, and during operation ofthe furnace there is a gradual accumulation of undesirable loose debrison the roof which necessitates periodic cleaning by manual methods. Theloose material insulates the roof and reduces its life.

The primary object of the present invention is to suspend refractorybricks at the roof of a metallurgical or like furnace by means includingsturdy pipes which are disposed in close proximity to the top or coldends of the roof bricks, and to enable these pipes to be used forcleaning of the top of the roof by arranging the pipes in communicationwith a line carrying air under pressure, and in some instances withsuction. The pipes may extend for substantially the full length of theroof parallel to or concentric to the transverse shape of the roof, andwill also be arranged in space relation for substantially the fulllength of the roof. Further, the pipes may be formed with openings insuch a manner as to direct blasts of compressed air on to the top of theroof, and, where feasible, to withdraw the resultant disturbed debristhrough openings in those of the pipes which are connected with asuction line. However, I have found that the roof can be mosteffectively cleaned by compressed air alone and so emitted from thepipes in sequence back along the length of the roof as to move thedebris from one end of the roof, along the length to the other end whereit is to be disposed of. Merely shaking loose the debris by compressedair and creating a cloud of debris which will settle somewhere else inthe general environment of the furnace installation is helpful; and theforegoing represent other objects of the invention.

In view of the fact that roofs of the kind under consideration are of asubstantial width, it is important to provide for uniform action of theair under pressure flow, and another object of the present invention isto accomplish this. Many of the foregoing effects are made possible by aregulating valve provided for each of the bricksuspending pipes in orderthat variable conditions can be taken into account, and such representsanother object of the present invention.

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in theaccompanying drawings which, by way of illustration, show a preferredembodiment of the present invention and the principles thereof and whatI now consider to be the best mode which I have contemplated forapplying these principles. Other embodiments of the invention embodyingthe same or equivalent principles may be used and structural changes maybe made as desired by those skilled in the art without departing fromthe present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a partial sectional view of an open-hearth furnace having aroof constructed in accordance with the present invention;

FIG. 2 is a partial sectional view illustrating details of thebrick-suspending pipes of the present invention;

FIGS. 3 and 4 are fragmentary elevations of the pipes takensubstantially and respectively on the line 33 and 4-4 of FIG. 2;

FIG. 5 is another form of roof construction in accordance with thepresent invention;

FIG. 6 is a view on an enlarged scale of a portion of the longitudinalextent of the roof shown in FIG. 5;

FIG. 7 is an end view of a furnace constructed in accordance withanother form of the present invention;

FIG. 8 is a detail sectional view of a portion of the roof structureshown in FIG. 7;

FIG. 9 is a side elevation of the roof illustrated in FIG. 7;

FIG. 10 is a sectional view on an enlarged scale of a portion of theroof shown in FIG. 9;

FIG. 11 is a sectional view illustrating another embodiment of thepresent invention; and

FIG. 12 is a fragmental elevation substantially on the line 1212 of FIG.11.

FIG. 1 of the drawing illustrates aspects of the present invention inrelation to a typical section through an openhearth furnace having theside Walls SW and a roof R of refractory bricks which in most instanceswill be basic bricks 10 arranged in a suspended arch style, and theopposite ends of the roof R are backed up in a conven tional manner byskew plate structure in turn arranged immeditaely above the side wallsSW.

As is well known in the art, the main supporting structure or frameworkfor an open-hearth furnace is altorded for the most part by structuralbeams, and this is particularly true insofar as the main support for thesuspended roof R is concerned. Thus, horizontal steel beams 11 are sosupported by upright beams 12 and 13 as to be spaced well above the backor so-called cold side of the roof defined by the tops of the bricks 10.Longitudinally extending beams 15 are supported in a conventional styleat the underside of the main support beams 11, and roof supporting hookmembers 16 of varying lengths are secured to the longitudinal beams 15to depend therefrom in the optimum spaced relationship.

Under the present invention, the bricks l!) are directly suspended bypipes 20 and 21 which will be described in more detail hereinbelow. Itwill be observed in FIG. 1 that the pipes 2d and 21 are in effectarcuate so as to be parallel or concentric to the shape of the roof R.These pipes have supporting plates 24 secured thereto in a rigid fashionas by welding, and the support plates 24 and the pipes 25) and 21, aswill be observed in FIG. I, extend for the full width of the roof R andare arranged in spaced parallel relation one behind the other forsubstantially the entire length of the roof R.

The brick elements ill can, of course, be of variant composition and areadvantageously encased in a rectangular steel casing 25 which has anextension 25E extending free of what will be the cold ends or top sides10H of bricks It) as shown in FIG. 2. Advantageously, hook-receivingopenings 30 or like hook-receiving elements are provided at the sides ofcasing extensions 25E that will abut one another inpairs along thelength of the roof in the assembled roof construction as shown in FIG.2. Attaching brackets 31 are saddled on the tops of the pipes 29 and 21,and these brackets have spread legs 31L that extend downward from thefore and aft sides of the associated pipes. The lowermost ends of thelegs 31L are bent upward at 31U, and the hooks thus afforded areconnected into openings 30 of abutted or op posed casing extensions asshown in FIG. 2, thereby 3 suspending the bricks directly below thepipes 20 and 21 with the lowermost side walls of the pipes in closeproximity to the tops or cold ends of the bricks. Such mode ofsuspension together with the extensions 25E afford channels C, FIG. 2,at the cold ends of the bricks, which channels extend from one side ofthe furnace to the other as will be apparent from FIGS. 1 and 2. Thissame relationship prevails with respect to the embodiment of theinvention shown in FIGS. 5 and 6 hereinafter described.

The pipes 20 and 21 are formed with openings, and means are afiorded toestablish a forced air flow through the pipes which will be'communicatedto the top of roof R through such openings. Accordingly, the top of theroof R will be subjectedto the disturbing influence of the air flow, andthis is sufficient to in effect swirl any loose debris that hasaccumulated at the top of the roof. This of itself in some instances issufficient to spread or spray the debris from the roof so that itsettles on the surrounding floor area. In other instances, as will beapparent from the description to follow, the pipes can be sequenced byautomatically controlled valves, so that the debris is movedprogressively from one end of the furnace roof to the other in graduallyincreasing amounts.

Under the presnt invention, this air flow can be the conjoint action ofair under high pressure and air under reduced pressure established byalternate ones of the pipes 20 and 21, or at least by selected of thepipes 26 and 21 as will now be explained.

Thus, under one form of the present invention, the pipes 20 are blowerpipes and are formed with round openings 35, FIG. 2, arranged in spacedrelation along the length of each pipe 20. The openings 35 are sooriented as to direct blasts of compressed air directly onto the tops ofthe bricks 1h. The other pipes 21 are suction pipes, and these pipeshave elongated openings 36 extended through the side walls thereof.

There are a pair of manifolds or headers 40 and 41, FIG. 1, which are toconduct air under high pressure, and additionally thereare a pairofrnanifolds 42 and 43 representing the suction lines. These are locatedat the opposite side of the roof in an elevated position and extendparallel to the length of the roof, that is, at right angles, to thepipes 29 and 21. As shown in FIG. 1, flow of air is induced in themanifold 41 by connecting the same to a source HP of air under highpressure which can take different forms. Thus, the source HP can be aconventional air compressor, or a blower or the like, and preferably aregulating valve V1, which can be shut off, is interposed in the airline between the pressure source HP and the inlet end of the manifold41. It is to be understood that the pressure manifold 40 at the oppositeside of the furnace is also connected in like manner to a source of airunder pressure.

The right-hand suction manifold 43 is connected to a standard vacuumsource VU such as an exhaust pump,

pulses of air under pressure, themselves sufficient to accomplish auseful purpose. as noted above and as will be evident hereinafter.

If desired, instead of affording separate sources HP and VII, there canbe one source connected by a header in each instance to the inlet endsof the manifolds 40 and 41 and the outlet ends of the manifolds 42 and43 respectively. V

The pipes 20 that are to, direct blasts of air onto the tops of the roofbricks are respectively connected adjacent their opposite closed orplugged ends to the pressure lected rows of bricks.

manifolds 40 and 4-1. Such connections include stub pipes as 45 whichare welded to the upper surfaces of the pipes 20 to be in communicationtherewith. The pipes 45 in turn are preferably connected to flexiblehoses 46 or the like, and the hoses 46 in turn communicate withregulating valves V3 which can be shut off. The valves V3 in turn areconnected to their pressure manifolds 40 and 41 by stub pipes of anappropriate size and dimension as shown in FIG. 1, depending of courseupon space relations that are involved. Advantageously, the valves V3can be solenoid valves capable of automatic sequencing as will beevident hereinafter.

It will berrealized that the valves V3 can be set to regulate the rateof flow of compressed air through the connections to the pipes 20, andmoreover, selected of these valves can be shut off to prevent entry ofcompressed air into selected of the pipes Ztl, depending upon theseverity of conditions that may be encounteredv The suction pipes 21 areconnected to their manifolds in a fashion substantially identical to themanner in which the pressure pipes are connected to their manifolds.

Thus, stub pipes are welded to the upper sides of the suction pipes 21,adjacent the opposite closed ends thereof, and these in turn are incommunication with flexible hoses 47 which in turn are connected toassociated regulating valves V4, the valves V4 having stub pipeconnections to the respective suction manifolds 42 and 43.

Another embodiment of the present invention is shown in FIGS. 5 and 6 inthe form of a so-called held-up helddown roof. In this instance, theblower pipes and suction'pipes 5t and 51, having openings as describedabove, are suspended by vertically disposed members formed to includethreaded shanks 53 which have the lower ends thereof retained by nutsand bolts in stub sockets 52 that in turn'are saddled on and welded tothe top sides of the aforesaid pipes at suitable spaced locations. Theshanks in turn are locked by nuts to supporting beams.

The bricks in this embodiment are also encased in metallic housingplates which have extensions formed with anchor openings in which arereceived hook arms 57 that in turn are saddled on and hung from thepipes 5t and 51 as above described. Thus, the bricks again are suspendedbelow the pipes, and the air-conducting pipes are centered above theopposed casing extensions as 255 in se- The pressure pipes 56, as shownin FIG. 5, have their ends in communication with inlets 60 for air underpressure, these inlets in turn being in communication with a compressedair manifold 61 through a manual regulating valve 62. Like connectionsand valving are afforded between suction manifolds 65 and the suctionpipes 51 to enable suction to be created, if desired, on the tops of thebricks, and the manifolds 61 and 65 are connected to suitable sources asdescribed above.

Advantageously, the bricks at selected locations are stabilized by largerectangular plates 67 having lower ends substantially flush with the hotor lower ends of the bricks. The upper ends of these plates areremovably secured in place, as by nuts and bolts, between a pair ofsupporting flanges 68 that are welded to and depend from the lower sidesof the pipes 50 and 51. Thus, the plates 67 are spaced or interposedbetween every four bricks along the longitudinal dimension of the roofas shown in FIG. 6, which is also the spacing of the pipes 50 and 51along the longitudinal extent of the roof, and as shown in FIG. 5 theplates 6'7 have a width of about six bricks across the lateral span ofthe roof arch, noting that the pipes 50 and 51 span the width of theroof.

In FIGS. 7 to 10, another form of roof construction within the purviewof the present invention is illustrated, and in this instance the roofRR is of the arch type, when viewed transversely, and has a front torear downward slope as is evident in FiG. 9. As in the foregoingembodiment, the bricks at the ends of the arch bear against skew plates1% and 101.

Upright columns and 106 are arranged at the opposite sides of thefurnace and have ends projecting up wardly above the outer or cold endof the roof structure as shown in FIG. 7. These uprights are spanned'byhorizontal beams 110 which in turn are supported by inclined braces 112and 113 which have ends respectively secured to the uprights 195 and thecross-beams 119.

Channel beams 120, FIG. 7, which extend for the length of the roof,repose on the cross beams 110 as best shown in FIG. 9, and the uppersurfaces of the channels 120 carry plates 122 which are secured theretoby welding. The plates 122 serve to support nuts 125 that are threadedon the uppermost ends of vertical support bolts 126 which are disposedwithin apertures in the plates 122 to hang therefrom. There are manysuch plates 122 and bolts 126 as illustrated in FIG. 9. The bolts are ofincreasing length proceeding from the front to the rear of the roof,this being in accordance with the front to rear slope of the roof RR.

The lower ends of the supports 126 are also threaded, and are extendedthrough openings in anchor plates 130 which in turn are secured tochannel beams 135 in the manner illustrated in FIG. 9. The channel beamsare therefore supported generally in a plane inclined in accordance withthe slope of the roof RR.

The channels 135 serve to support directly the suspending tubes or pipes139 which in turn are arranged in accordance with the present inventionto allow the bricks to be cleaned of debris at the cold ends thereof,while at the same time enabling the bricks to be supportedadvantageously in a stabilized manner.

Thus, the pipes 139, as shown in FIG. 7, are bowed to conform to theroof arch, being concentric to the transverse shape of the roof RR, inorder that the bricks will be uniformly acted upon when air underpressure is pro vided as will hereinafter be explained. The pipes 139are spaced one from another in a front to rear relation ship along thelength of the roof as will be evident in FIG. 9.

The pipes or tubes 139 are of course hollow and are spaced slightlyabove the upper cold ends of the bricks 140. The pipes are provided withapertures 139A and 139B, FIGS. 8 and 10, so oriented one wi h respect toanother as to direct jets of compressed air downwardly onto the tops orcold ends of the bricks 140 in order to facilitate removal of debris orloose refractory that has accumulated at the top of the roof.

The bricks are supported in the manner explained above in connectionwith the first embodiment of the invention. Thus, each brick 146includes a core 1411C of refractory material and a metallic casing ofsteel or like ferrous alloy 140M which surrounds all four sides of thebrick. The metallic casing includes at least two tabs 144 and 145, FIG.10, which extend beyond the free or cold end of the refractory core 149Cand these tabs or ears are provided with openings 144A and 145A in whichcan be inserted the hooked ends 141 and 142 of a support wire 150 whichis bent over to be supported by the pipes as 139. Thus, the supporter orhanger 150 is substantially of inverted V-form including a pair ofoutwardly extending leg elements having the hook portions 141 and 142 atthe free ends thereof, and these hook portions are used to hold theprojecting ends of the abutting metallic casings that surround adjacentones of the bricks. It will be appreciated from FIG. 9 that there needbe a pipe as 139 for every four bricks since each hooked end of thesupport 150 will support a pair of bricks.

In order to stabilize the roof and to assure further rigidity duringactual operation as may be occasioned by the oxidation involved,relatively large stabilizer plates 155 are hung from the pipes 139 so asto be disposed between an adjacent pair of bricks considered in a frontto rear sense.- To this end, flange plates 153 and 154 are welded inspaced, depending relation to the underside of each pipe 139. The flangeplates are used to support a pair of nuts and bolts N1 and N2, FIG. 8,which extend normal to the planes of the plates 153 and 154 to serve assupports for the stabilizer plates 155. Thus, the stabilizer plates 155are of rectangular shape, and at the upper edge thereof are formed withbayonet slots S1 and S2 which enable the stabilizer plates to be movedupwardly past the bolt assembly N1 and N2 and then shifted to the leftor right, however viewed, to present the right angled legs of the slotsS1 and S2 to the supporting bolt assembly N1 and N2. It will beappreciated that this is accomplished as a preliminary assembly prior tothe bricks 140 being put in place.

Air under pressure is furnished to the pipes 139 by a header or manifold165 which has supply tubes, hoses or the like 166 in communicationtherewith and connected to normally closed solenoid valves as 168. Theoutput side of each valve 168 is connected by a conduit 169 or the liketo a related one of the pipes 139 substantially at the mid-point of thelength thereof as shown in FIG. 7. The pipes 139 have dead ends andconsequently, when a valve 168 is opened, air under pressure in themanifold 165 rushes into the pipe 139 and emits in jet streams throughthe openings 139A and 139B.

The foregoing arrangement enables the pipes 139 to be sequenced sincethe valves 168, being of the solenoid type, can be operated remotely andautomatically and, by proper timing, in any desired sequence and rate.Thus, for example, the valve 168 to be associated with the first orforwardmost one of the pipes 139 could be actuated or opened first for abrief duration, then the valve for the next pipe and the valve for thenext pipe, and so on down the line timed to move a cloud of debrisgradually from the front of the furnace to the rear.

The pipes 170, shown in FIG. 12, in turn are carried by elongatedU-straps 171 having the free ends of the legs 170L thereof threaded. Thethreaded ends of the straps 171 are extended through anchor plates 172supported by beams BL and nuts 171N are provided on the ends of the legs17ilL that project above the plate 172.

In FIGS. 11 and 12 another embodiment of the present invention isillustrated in association With a refractory roof RR which is flatrather than arcuate. Here, the bricks which afford the roof RR are ofthe basic type encased in metallic sleeves 160M as in the foregoingembodiment. These sleeves or casings include extensions 160E providedwith apertures which receive the hooked ends 164 and of support wires166 which in turn are supported by and depend from pipes adapted tocarry air under pressure.

As in the foregoing embodiment the pipes 170 are parallel to thetransverse shape of the roof and are provided with apertures which willdirect jet streams of compressed air on to the tops or cold ends of thebricks to remove debris therefrom in the manner described above.

It may be noted, however, that in this instance of the flat roof thepipes 170, as shown in FIG. 11, advantageously extend from a remote sideof the roof approximately to the mid-point of the roof where the pipe iscapped at 170C to afford a dead end. A similar pipe 170 having a deadend cap 170C-1 extends from the midpoint of the roof as viewed in FIG.11 to the right-hand (not visible) remote side of the roof.

Each such pipe 170 at its uncapped end communicates with a hose 173which communicates in turn with a manifold 175 through a valve 177adapted to be sequenced in the manner described above to gradually movea cloud of debris step-by-step from the front of the roof to the rearor, for that matter, in the opposite direction, depending upon thenature of the installation.

It will be seen from the foregoing that the-present in vention makes itpossible to remove debris from the top of the roof of a furnaceaffordedby basic refractory bricks, and at the same time the inventionaffords a convenient way of suspending the bricks while making provisionfor the installation of stabilizer plates. Hence, while I haveillustrated and described preferred embodiments of my invention it is tobe understood that these are capable of variation and modification, andI there- 7 a T fore do not wish to be limited to'the precise details setforth, but desire to avail myself of such" changes and alterations asfall within the purview of the following claims.

I claim: 7

1. In a furnace of the kind described, a suspended roof of refractorybricks subject to accumulations of debris during use of the furnace;means for suspending said bricks including a plurality of spacedbrick-supporting pipes disposed over the tops of the bricks incloseproximity thereto, selected of said pipes being connected to a source ofairjunder pressure, and said pipes having spaced openings in the wallsthereof throughout substantially the entire length thereof enablingblasts of air under pressure to be directed onto the tops of saidbricks, incidental to loosening and removing the debris from the tops ofthe bricks 2. In a furnace-ofthe kind described, a suspended roof ofrefractory bricks subject to accumulations of debris during use of thefurnace, means for suspending said bricks including aplurality of spacedbrick-supporting pipes disposed: over the topsof the bricks in closeproximity thereto, said pipes being arranged substantially in parallelrelation one to another, said pipes extending for substantially the fulltransverse width of the roof and being'spaced' throughout substantiallythe full longitudinal extent of the roof, said pipes having spacedopenings in the walls thereof throughout substantially the entire lengththereof and in close proximity to the tops; of the bricks to effectivelydirect jets of air thereagainst', and said pipes being connected toamanifold which in turn is connected to means for creating a forced flowof air through said manifold and'pipes to create a disturbing air flowon the'tops of said bricks to loosen accumulations of debris collectedthereon; I

3. A furnace according to claim 2 wherein regulating valves means areinterposed between said manifold and means are automatically sequencedtoproduce' gradual loosening of the debris step-wise through the pipesfrom one end of the roof to the other.

5. In a furnace, a suspended roof spanning ap-air of side-walls andbeing constructed of transverse rows of refractory bricks which rowsextend from one side of the furnace across the width of the roof'to theother side, said bricks having hot lower ends 'that face the combust-ionarea of the furnace and said bricks having cold upper ends that definethe top of the roof, the cold ends of the bricks being subject togradual deterioration during use of the furnace whereby refractorydebris tends to accumulate at the top of the roof, a plurality ofairconducting pipes disposed over the cold upper ends of the bricks inclose proximity thereto, said pipes being spaced throughout the lengthof the roof so that several rows of bricks across the width of the rooflie between adjacent pipes, said bricks each having: a refractory coreand a metallic casing extending therea bout, said casings havingprojections at the cold ends of the bricks that extend beyond the coldends of the refractory cores tobe free thereofand which are in abuttingback-to-back relationship across the width of the roof to affordchannels that extendacrbss the arch of the roof, hangers secured to saidpipes and having leg portions depending below 1 said pipes on oppositesides thereof, said leg portions of the hangers being secured to abuttedcasingexte'nsions on opposite sides of the pipes whereby each of thehangers oneach pipe is effective to suspend several bricks betweenadjacent'pipes, said pipes each having spaced openingsthereinsubstantially uniformly throughout the length thereof for communicatingair flow in the pipes to the tops of the bricks to swirl and disturb anydebris thereon, and means connected to said pipes-for creating at will aforced flow of airthere through to be communicated to the tops of saidbricks through the openings in said pipes as aforesaid.

6. In a furnace, a suspended arch-shaped roof spanning a pair of sidewalls and being constructed of transverse rows of refractory brickswhich rows extend from one side of the furnace across the width of theroof to the other side, said bricks having hot lower ends that face thecombustion area of the furnace and said bricks having col-d upper endsthat define the top of the roof, the cold ends of the bricks beingsubject to gradual deterioration during use of the furnace wherebyrefractory debris tends to accumulate at the top of the roof, aplurality of air-conducting pipes disposed over the cold upper ends ofthe bricks in close proximity thereto and each of said pipes being ofarcuate form to be substantially concentric to the arch of the roof,said pipes being spaced throughout the length of the roof so thatseveral rows of bricks lie between adjacent pipes, said bricks eachhaving a refractory core and a metallic casing extended thereabout, saidcasings having projections at the cold ends of the bricks that extendbeyond the cold ends of the refractory cores to be free thereof andwhich are opposite one another in rows across the span of the roof, saidpipes being spaced throughout the length of the roof so that severalrows of bricks across the arch lie between adjacent pipes and so thatthe pipes are centered above selected rows of the opposed casingextensions, hangers secured to said pipes and having leg portionsdepending below said pipes on opposite sides thereof, said leg portionsof the hangers being secured to opposed casing extensions on oppositesides of the pipes whereby each of the hangers on each pipe is effectiveto suspend several bricks between adjacent pipes, stabilizer platessecured to and depending from said pipes and being disposed between thecasings having opposed extensions above which the pipes are centered asaforesaid, said pipes each having spaced openings therein substantiallyuniformly throughout the length thereof for communicating air flow inthe pipes to the tops of the bricks to swirl and disturb any debristhereon, and means connected to said pipes for creating at will a forcedflow of air therethrough to be communicated to the tops of said bricksthrough the openings in said pipes.

7. In a furnace, a roof spanning a pair of side walls and beingconstructed of transverse rows of refractory bricks which rows extendfrom one side of the furnace across the arch to the other side, saidbricks having hot lower ends that face the combustion area of thefurnace and said bricks having cold upper ends that define the top ofthe roof, the cold ends of the bricks being subject to gradualdeterioration during use of the furnace whereby refractory debris tendsto accumulate at the top of the roof, a plurality of air-conductingpipes disposed over the cold upper ends of the bricks in close proximitythereto, said pipes being spaced throughout the length of the roof sothat several rows of bricks across the arch lie between adjacent pipes,said bricks each having a refractory core and a metallic casing extendedthereabout, said casings having projections at the cold ends of thebricks that extend beyond the cold ends of the refractory cores to befree thereof and which are in opposed relationship across the span ofthe roof, hangers secured to said pipes and having leg portionsdepending below said pipes on opposite sides thereof, said legportionsof the hangers being secured to opposed casing extensions on oppositesides of pipes whereby each of the hangers on each pipe is effective tosuspend several rows of bricks between adjacent pipes, said pipes eachhaving spaced openings therein substantially uniformly throughout thelength thereof for communicating air flow in the pipes to the tops ofthe bricks to swirl and disturb any debris thereon, and means connectedto said pipes for creating at will .a forced'fiow of air therethrough tobe communicated, to the tops of said bricks through the openings in saidpipes as aforesaid, the last-named means including manifolds connectedto said pipes and means for supply- 9 ing air under pressure incontrolled amounts to said manifolds.

8. In a furnace, a suspended roof spanning a pair of side walls andbeing constructed of transverse rows of refractory bricks which extendfrom one side of the furnace across the arch to the other side, saidbricks having hot lower ends that face the combustion area of thefurnace and said bricks having cold upper ends that define the top ofthe roof, the cold ends of the bricks being subject to gradualdeterioration during use of the furnace whereby refractory debris tendsto accumulate at the top of the roof, a plurality of air-conductingpipes disposed over the cold ends of the bricks in close proximitythereto, said pipes being spaced throughout the length of the roof sothat several rows of bricks across the arch lie between adjacent pipes,means secured to said pipes and suspending several bricks in each row onopposite sides of each pipe, said pipes each having spaced openingstherein substantially uniformly throughout the length 10 thereof forcommunicating air flow in the pipes to the tops of the bricks to swirland disturb any debris thereon, and means connected to said pipes forcreating at will a forced flow of air therethrough to be communicated tothe tops of said bricks through the openings in said pipes as aforesaid.

9. A furnace according to claim 8 wherein the lastnamed means includesmanifolds connected to said pipes and means for supplying air underpressure in controlled amounts to said manifolds.

References Cited in the file of this patent UNITED STATES PATENTS1,488,468 Bigelow Apr. 1, 1924 1,894,297 Snow et a1. Ian. 17, 19331,966,190 Snow July 10, 1934 2,110,533 Snow et a1 Mar. 8, 1938 3,005,424Heuer Oct. 24, 1961

1. IN A FURNACE OF THE KIND DESCRIBED, A SUSPENDED ROOF OF REFRACTORYBRICKS SUBJECT TO ACCUMULATIONS OF DEBRIS DURING USE OF THE FURNACE,MEANS FOR SUSPENDING SAID BRICKS INCLUDING A PLURALITY OF SPACEDBRICK-SUPPORTING PIPES DISPOSED OVER THE TOPS OF THE BRICKS IN CLOSEPROXIMITY THERETO, SELECTED OF SAID PIPES BEING CONNECTED TO A SOURCE OFAIR UNDER PRESSURE, AND SAID PIPES HAVING SPACED OPENINGS IN THE WALLSTHEREOF THROUGHOUT SUBSTANTIALLY THE ENTIRE LENGTH THEREOF ENABLINGBLASTS OF AIR UNDER PRESSURE TO BE DIRECTED ONTO THE TOPS OF SAIDBRICKS, INCIDENTAL TO LOOSENING AND REMOVING THE DEBRIS FROM THE TOPS OFTHE BRICKS.